Heather, thanks for full reply.
Yes, looks like its the scale/score authors that I am criticising, such as the Borg scale.
But the new DV_SCALE I am unclear about, as it “allows us to handle real number rather than just integers” Clinical scales - ordinal or coded text? - #18 by ian.mcnicoll
I understand that integers are already real numbers , the issue was to support fractional numbers like 2.5.
But I think that both 2 and 2.5 here (in Borg) are not real numbers either: these ordinal numbers are all not simply calculable despite appearances.
So should the datatype be non-calculable i.e. DV_CODED_TEXT ?

If the scale author is using ordinal numbers badly, should openEHR persist this error by allowing it to compute as if a real number?

I see that DV_ORDINAL shows value Integer, and that DV_SCALE shows value Real. These display the “number” from the original scale correctly, but don’t they also make both these calculable - which for ordinals they should not be?

If the scale author is using ordinal numbers badly, should openEHR persist this error by allowing it to compute as if a real number?

Yes - we are here to build systems and applications. The most common use of ordinals is as the sub-element of a score - calculated from these sub-scores.

Is there an argument that these are pseudo-science - sure but not our job (or within our gift) to correct that by imposing technical constraints.

Heather summed up the realities nicely. DV_SCALE was introduced precisely because of Borg scale and some others - I agree it is dumb but what do we do when we are asked to implement it?

A better approach IMO is to embed informatics when these things are created or added to guidance like NICE. Stop the nonsense at source

Well they do, if you don’t know what a ‘scale’ or ‘score’ or an ‘ordinal’ is in health / healthcare IT
Which of course, no-one knows until someone tells them at coffee at some conference…

So, it’s sort of arcane knowledge in our domain. I don’t think we can do much about it.

BTW, we only have both DV_SCORE and DV_SCALE because originally we didn’t realise there were scores with decimal numbers in them. Obviously the authors of such things should have been arrested for crimes against mathematics and health informatices, but since they weren’t we live with a) ‘scales’ as well, and b) the implication that because real numbers are used, they really could be computed with in a quantitative sense - neither of which are necessary or desirable.

OK, thanks for discussion.
So if we acknowledge that some of these scales are garbage, it’s a GIGO issue. The scores are valid if using scales as designed and validated i.e. low-resolution scales (not more than 5 datapoints so at 1 digit) suitable for mental arithmetic by clinicians in live context for safety-checking.

Is it agreed that the inadvertent transform of these ordinal symbols into computable real numbers may be harmful?
Thinking of further “calculations” using incorrect maths so the essentially unpredictable output is loss of precision - as we all suspect for these scores. I will need to ponder if a Clinical Risk Assessment approach is feasible.

Please do move this elsewhere as you would know best.

It possibly could be. I think those managing operational clinical contexts need to take come responsibility for procuring or otherwise developing solutions, apps etc that don’t contain ‘inadvertent’ misuse of data. That would be a clinical safety issue. So vendors and devs need to know some basic health informatics and have access to health informaticians and clinicians at various points in the development process.

Whilst I agree that there is a lot of pseudo-science involved in many of these scores and scales, and the clinical community definitely needs to impose more rigour and informatics input, I’m not sure they represent a true patient risk, unless there is an attempt to over-engineer and make assumptions that their individual or computed scores have some kind of real independent biological meaning .

They are (or so we are led to believe) useful compressions of more real-world inputs that guide treatment and decision. I don’t see the use of numerics inside as being inherently risky.

The Editorial work and community review process has input from a clinical safety POV. If a score or scale has been validated with numerics we represent this as per the validated paper/evidence. We do endeavour to understand the academic intent and represent it in the archetype to support appropriate and safe implementation.

Should they be represented using the new data type, or retrofitted to published ones? Maybe. That is a decision for Editors as a policy if and when the data type is made available in the tooling.

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siljelb
(Silje Ljosland Bakke)
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